1. Field of the Invention
This invention relates to a data communication system, data communication method, data receiver and data receiving method configured to automatically construct a user's virtual environment on the basis of data transmitted through a communication path.
2. Description of the Related Art
Computers and other information devices, and especially personal computers, have recently been distributed in large number. In general, a user must install desired software, i.e. computer programs, in a computer to use the software on the computer. Although many computers in the market are already installed with predetermined computer programs, later operations for updating the programs, or the like, rely on users' own tasks.
As computer programs become more and more sophisticated and multi-functional, there is the tendency of composing each program using fractional components to permit individual users to install selective components necessary for their desired functions and to thereby alleviate loads on hard discs, memories and other resources in computers.
Additionally, computer networks represented by the Internet are expanding. Moreover, many computer programs are now provided and installed in computers by down-loading through networks. In most cases, also for alleviating the load to networks, only the necessary parts of the component-type computer programs are down-loaded,
On the other hand, when receiving satellite broadcasting, for example, an IRD (Integrated Receiver Decoder) is used to effectuate conditional access to the broadcast. The IRD includes a tuner designating a reception transponder, a demodulator, a descrambler, a demultiplexer for designating separated packets, an image decoder and an audio decoder, among others, to control the selective supply of programs to individual users, for example. The IRD has a built-in CPU and a controller including RAM and ROM, and is controlled by software written in ROM.
Also, in the IRD, the software is occasionally renewed (up-graded) to cope with changes or renewal of broadcasting programs made on the part of the station, new services, and changes in key information for descrambling, for example. Concerning such renewal of IRD software, it is proposed to transmit the program data through the satellite broadcasting waves to be down-loaded by the IRD and to be written in ROM by a predetermined loader program. In this manner, it is sufficient for a user to request down-loading of the new-version of software, and the software is renewed automatically in his IRD.
As referred to above, operations for installing software in computers or up-grading software have relied on manual tasks of users. These jobs are troublesome, and occasionally cause mistakes.
Further, many computer programs down-loaded through networks require another particular computer program for installing them successfully. If a user does not have the particular computer program required for the install, the particular program must also be down-loaded. Additionally, it takes much time and labor to construct the user's necessary environment for his purpose.
Moreover, there are large differences in skill level of users of computers or other information devices. For example, a computer program may include functions which beginners will never use. Nevertheless, beginners are compelled to install the full program including modules for undesired functions, this results in wasting resources.
Also for high-grade users, there is the problem that they have to install the software using the same procedure as beginners do, and they have additional jobs after the install to construct their desired environments, such as deletion of unnecessary files, for example.
In the case of IRD, users could have the software down-loaded loaded and installed automatically by performing predetermined operations. In this case, however, new version software is merely provided, and it is impossible to have only user's desirable portions selectively down-loaded and installed.